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Maluda MCM, Johnson E, Robinson F, Jikal M, Fong SY, Saffree MJ, Fornace KM, Ahmed K. The incidence, and spatial trends of cholera in Sabah over 15 years: Repeated outbreaks in coastal areas. PLOS Glob Public Health 2024; 4:e0002861. [PMID: 38289918 PMCID: PMC10826939 DOI: 10.1371/journal.pgph.0002861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 01/07/2024] [Indexed: 02/01/2024]
Abstract
Vibrio cholerae remains a notable public health challenge across Malaysia. Although the Malaysian state of Sabah is considered a cholera-affected area, gaps remain in understanding the epidemiological trends and spatial distribution of outbreaks. Therefore, to determine longitudinal and spatial trends in cholera cases data were obtained from the Sabah State Health Department for all notified cases of cholera between 2005-2020. A cholera outbreak is defined as one or more confirmed cases in a single locality with the evidence of local transmission. All records were geolocated to village level. Satellite-derived data and generalised linearized models were used to assess potential risk factors, including population density, elevation, and distance to the sea. Spatiotemporal clustering of reported cholera cases and zones of increased cholera risk were evaluated using the tau statistic (τ) at 550m, 5km and 10km distances. Over a 15-year period between 2005-2020, 2865 cholera cases were recorded in Sabah, with a mean incidence rate of 5.6 cases per 100,000 (95% CI: 3.4-7.9). From 2015-2020, 705 symptomatic cases and 727 asymptomatic cases were reported. Symptomatic cases primarily occurred in local Malaysian populations (62.6%, 441/705) and in children and adolescents under 15-years old (49.4%, 348/705). On average, cases were reported in areas with low population density (19.45 persons/km2), low elevations (19.45m) and near coastal areas. Spatiotemporal clustering of cholera cases was identified up to 3.5km, with increased village-level cholera risk within 500m and 5 days of initial case presentation to a health facility (Risk Ratio = 9.7, 95% CI: 7.5-12.4). Cholera incidence has high spatial and temporal heterogeneity within Sabah, with some districts experiencing repeated outbreaks. Cholera cases clustered across space and time, with village-level risk of cholera highest within 5 days and within close proximity to primary case villages, suggesting local transmission.
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Affiliation(s)
- Marilyn Charlene Montini Maluda
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
- Sabah State Health Department, Ministry of Health Malaysia, Kota Kinabalu, Sabah, Malaysia
| | - Emilia Johnson
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Fredie Robinson
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Muhammad Jikal
- Sabah State Health Department, Ministry of Health Malaysia, Kota Kinabalu, Sabah, Malaysia
| | - Siat Yee Fong
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Mohammad Jeffree Saffree
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Kimberly M. Fornace
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
- Faculty of Infectious and Tropical Diseases and Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Kamruddin Ahmed
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
- Research Center for Global and Local Infectious Diseases, Oita University, Oita, Japan
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Fornace KM, Zorello Laporta G, Vythilingham I, Chua TH, Ahmed K, Jeyaprakasam NK, de Castro Duarte AMR, Amir A, Phang WK, Drakeley C, Sallum MAM, Lau YL. Simian malaria: a narrative review on emergence, epidemiology and threat to global malaria elimination. Lancet Infect Dis 2023; 23:e520-e532. [PMID: 37454671 DOI: 10.1016/s1473-3099(23)00298-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/19/2023] [Accepted: 04/28/2023] [Indexed: 07/18/2023]
Abstract
Simian malaria from wild non-human primate populations is increasingly recognised as a public health threat and is now the main cause of human malaria in Malaysia and some regions of Brazil. In 2022, Malaysia became the first country not to achieve malaria elimination due to zoonotic simian malaria. We review the global distribution and drivers of simian malaria and identify priorities for diagnosis, treatment, surveillance, and control. Environmental change is driving closer interactions between humans and wildlife, with malaria parasites from non-human primates spilling over into human populations and human malaria parasites spilling back into wild non-human primate populations. These complex transmission cycles require new molecular and epidemiological approaches to track parasite spread. Current methods of malaria control are ineffective, with wildlife reservoirs and primarily outdoor-biting mosquito vectors urgently requiring the development of novel control strategies. Without these, simian malaria has the potential to undermine malaria elimination globally.
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Affiliation(s)
- Kimberly M Fornace
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK; Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore; Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
| | - Gabriel Zorello Laporta
- Graduate Research and Innovation Program, Centro Universitario FMABC, Santo André, São Paulo, Brazil
| | | | | | - Kamruddin Ahmed
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia; Borneo Medical and Health Research Centre, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Nantha K Jeyaprakasam
- Biomedical Science Programme, Center for Toxicology and Health Risk Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Ana Maria Ribeiro de Castro Duarte
- Laboratory of Protozoology, Institute of Tropical Medicine of São Paulo, Universidade de São Paulo, São Paulo, Brazil; Instituto Pasteur, Secretaria de Estado da Saude de São Paulo, São Paulo, Brazil
| | - Amirah Amir
- Department of Parasitology, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Wei Kit Phang
- Department of Parasitology, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Maria Anice M Sallum
- Departamento de Epidemiologia, Faculdade de Saude Publica, Universidade de São Paulo, São Paulo, Brazil
| | - Yee Ling Lau
- Department of Parasitology, Universiti Malaya, Kuala Lumpur, Malaysia
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Naserrudin NA, Lin PYP, Monroe A, Baumann SE, Adhikari B, Miller AC, Sato S, Fornace KM, Culleton R, Cheah PY, Hod R, Jeffree MS, Ahmed K, Hassan MR. Disentangling the intersection of inequities with health and malaria exposure: key lessons from rural communities in Northern Borneo. Malar J 2023; 22:343. [PMID: 37946259 PMCID: PMC10636872 DOI: 10.1186/s12936-023-04750-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 10/11/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND The increasing incidence of Plasmodium knowlesi malaria poses a significant challenge to efforts to eliminate malaria from Malaysia. Macaque reservoirs, outdoors-biting mosquitoes, human activities, and agricultural work are key factors associated with the transmission of this zoonotic pathogen. However, gaps in knowledge regarding reasons that drive malaria persistence in rural Kudat, Sabah, Northern Borneo remain. This study was conducted to address this knowledge gap, to better understand the complexities of these entangled problems, and to initiate discussion regarding new countermeasures to address them. This study aims to highlight rural community members' perspectives regarding inequities to health relating to P. knowlesi malaria exposure. METHODS From January to October 2022, a study using qualitative methods was conducted in four rural villages in Kudat district of Sabah, Malaysia. A total of nine in-depth interviews were conducted with community and faith leaders, after the completion of twelve focus group discussions with 26 photovoice participants. The interviews were conducted using the Sabah Malay dialect, audio-recorded, transcribed, and translated into English. The research team led the discussion and analysis, which was approved by participants through member checking at the community level. RESULTS Participants identified disparity in health as a key issue affecting their health and livelihoods. Injustice in the social environment was also identified as a significant challenge, including the importance of listening to the voices of affected communities in disentangling the social and economic phenomena that can impact malaria control. Specific concerns included inadequate access to health-related resources and degradation of the environment. Participants recommended improving access to water and other necessities, increasing the availability of malaria control commodities in healthcare facilities, and developing sustainable programs to reduce socioeconomic disparities. CONCLUSION Inequities to health emerged as a key concern for malaria control in rural Kudat, Sabah. A locally targeted malaria programme cantered on improving the social and economic disparities associated with health outcomes, could be a potential strategy for malaria prevention in such areas. Community-level perspectives gathered from this study can be used as a foundation for future discussions and dialogues among policymakers and community members for achieving greater transparency, improving social equity, and interoperability in addressing P. knowlesi malaria control.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Sabah, Malaysia
- Sabah State Health Department, Ministry of Health, 88590, Kota Kinabalu, Malaysia
| | - Pauline Yong Pau Lin
- Faculty of Social Sciences and Humanities, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - April Monroe
- Johns Hopkins Center for Communication Programs, Baltimore, MD, USA
| | - Sara Elizabeth Baumann
- Department of Behavioral and Community Health Sciences, University of Pittsburgh School of Public Health, Pittsburgh, PA, 15261, USA
| | - Bipin Adhikari
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Shigeharu Sato
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Sabah, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Kimberly M Fornace
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, 791-0295, Japan
| | - Phaik Yeong Cheah
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- The Ethox Centre, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Rozita Hod
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia
| | - Mohammad Saffree Jeffree
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Sabah, Malaysia
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Kamruddin Ahmed
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Sabah, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Mohd Rohaizat Hassan
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia.
- Borneo Medical and Health Research Centre, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Sabah, Malaysia.
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Naserrudin NA, Jiee SF, Habil B, Jantim A, Mohamed AFB, Dony JJF, Ibrahim SSA, Fornace KM, Hassan MR, Jeffree MS, Hod R, Culleton R, Ahmed K. The public health response to a Plasmodium malariae outbreak in Penampang district, Sabah during a COVID-19 movement control order. Malar J 2023; 22:292. [PMID: 37789320 PMCID: PMC10546630 DOI: 10.1186/s12936-023-04693-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 08/29/2023] [Indexed: 10/05/2023] Open
Abstract
BACKGROUND Since 2018, no indigenous human malaria cases has been reported in Malaysia. However, during the recent COVID-19 pandemic the World Health Organization is concerned that the pandemic might erode the success of malaria control as there are reports of increase malaria cases in resource limited countries. Little is known how the COVID-19 pandemic has impacted malaria in middle-income countries like Malaysia. Here the public health response to a Plasmodium malariae outbreak occurred in a village in Sabah state, Malaysia, during a COVID-19 movement control order is reported. METHODS An outbreak was declared following the detection of P. malariae in July 2020 and active case detection for malaria was performed by collecting blood samples from residents residing within 2 km radius of Moyog village. Vector prevalence and the efficacy of residual insecticides were determined. Health awareness programmes were implemented to prevent future outbreaks. A survey was conducted among villagers to understand risk behaviour and beliefs concerning malaria. RESULTS A total of 5254 blood samples collected from 19 villages. Among them, 19 P. malariae cases were identified, including the index case, which originated from a man who returned from Indonesia. His return from Indonesia and healthcare facilities visit coincided with the movement control order during COVID-19 pandemic when the healthcare facilities stretched its capacity and only serious cases were given priority. Despite the index case being a returnee from a malaria endemic area presenting with mild fever, no malaria test was performed at local healthcare facilities. All cases were symptomatic and uncomplicated except for a pregnant woman with severe malaria. There were no deaths; all patients recovered following treatment with artemether-lumefantrine combination therapy. Anopheles balabacensis and Anopheles barbirostris were detected in ponds, puddles and riverbeds. The survey revealed that fishing and hunting during night, and self-treatment for mild symptoms contributed to the outbreak. Despite the index case being a returnee from a malaria-endemic area presenting with mild fever, no malaria test was performed at local healthcare facilities. CONCLUSION The outbreak occurred during a COVID-19 movement control order, which strained healthcare facilities, prioritizing only serious cases. Healthcare workers need to be more aware of the risk of malaria from individuals who return from malaria endemic areas. To achieve malaria elimination and prevention of disease reintroduction, new strategies that include multisectoral agencies and active community participation are essential for a more sustainable malaria control programme.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Bangi, Malaysia
- Sabah State Health Department, Ministry of Health, Kota Kinabalu, Malaysia
| | - Sam Froze Jiee
- Department of Community Medicine and Public Health, Faculty of Medicine and Health Sciences, Universiti Malaysia Sarawak, Kota Samarahan, Malaysia
| | - Bobby Habil
- Penampang District Health Office, Ministry of Health, Kota Kinabalu, Malaysia
| | - Anisah Jantim
- Penampang District Health Office, Ministry of Health, Kota Kinabalu, Malaysia
| | | | | | | | - Kimberly M Fornace
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
- Faculty of Infectious and Tropical Diseases and Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore, Singapore
| | - Mohd Rohaizat Hassan
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Mohammad Saffree Jeffree
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Rozita Hod
- Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | | | - Kamruddin Ahmed
- Borneo Medical Health and Research Centre,, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia.
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia.
- Research Center for Global and Local Infectious Diseases, Oita University, Oita, Japan.
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Fornace KM, Drakeley CJ, Lindblade KA, Jelip J, Ahmed K. Zoonotic malaria requires new policy approaches to malaria elimination. Nat Commun 2023; 14:5750. [PMID: 37717079 PMCID: PMC10505154 DOI: 10.1038/s41467-023-41546-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/06/2023] [Indexed: 09/18/2023] Open
Abstract
WHO guidelines for classification of malaria elimination in a country require that the risk of human infection from zoonotic, as well as nonzoonotic, malaria parasites is negligible. In this Comment, the authors discuss the implications of this policy for countries, such as Malaysia, with no recent reported nonzoonotic cases but ongoing zoonotic transmission.
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Affiliation(s)
- Kimberly M Fornace
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK.
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | | | | | - Kamruddin Ahmed
- Borneo Medical and Health Research Centre, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
- Research Center for Global and Local Infectious Diseases, Oita University, Oita, Japan
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Byrne I, William T, Chua TH, Patterson C, Hall T, Tan M, Chitnis C, Adams J, Singh SK, Grignard L, Tetteh KKA, Fornace KM, Drakeley CJ. Serological evaluation of risk factors for exposure to malaria in a pre-elimination setting in Malaysian Borneo. Sci Rep 2023; 13:12998. [PMID: 37563178 PMCID: PMC10415323 DOI: 10.1038/s41598-023-39670-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 07/28/2023] [Indexed: 08/12/2023] Open
Abstract
Malaysia has reported no indigenous cases of P. falciparum and P. vivax for over 3 years. When transmission reaches such low levels, it is important to understand the individuals and locations where exposure risks are high, as they may be at greater risk in the case of a resurgence of transmission. Serology is a useful tool in low transmission settings, providing insight into exposure over longer durations than PCR or RDT. We ran blood samples from a 2015 population-based survey in northern Sabah, Malaysian Borneo on a multiplex bead assay. Using supervised machine learning methods, we characterised recent and historic exposure to Plasmodium falciparum and P. vivax and found recent exposure to P. falciparum to be very low, with exposure to both species increasing with age. We performed a risk-factor assessment on environmental, behavioural, demographic and household factors, and identified forest activity and longer travel times to healthcare as common risk-factors for exposure to P. falciparum and P. vivax. In addition, we used remote-sensing derived data and geostatistical models to assess environmental and spatial associations with exposure. We created predictive maps of exposure to recent P. falciparum in the study area and showed 3 clear foci of exposure. This study provides useful insight into the environmental, spatial and demographic risk factors for P. falciparum and P. vivax at a period of low transmission in Malaysian Borneo. The findings would be valuable in the case of resurgence of human malarias in the region.
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Affiliation(s)
- Isabel Byrne
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK.
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- Gleneagles Hospital, Kota Kinabalu, Malaysia
- Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Malaysia
| | - Tock H Chua
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Catriona Patterson
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK
| | - Tom Hall
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK
| | - Mark Tan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK
| | - Chetan Chitnis
- Department of Parasites and Insect Vectors, Malaria Parasite Biology and Vaccines, Institut Pasteur, Paris, France
| | - John Adams
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Susheel K Singh
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Lynn Grignard
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK
| | - Kevin K A Tetteh
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK
| | - Kimberly M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, Scotland
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK
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Macalinao MLM, Fornace KM, Reyes RA, Hall T, Bareng APN, Adams JH, Huon C, Chitnis CE, Luchavez JS, Tetteh KK, Yui K, Hafalla JCR, Espino FEJ, Drakeley CJ. Analytical approaches for antimalarial antibody responses to confirm historical and recent malaria transmission: an example from the Philippines. Lancet Reg Health West Pac 2023; 37:100792. [PMID: 37693871 PMCID: PMC10485684 DOI: 10.1016/j.lanwpc.2023.100792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 03/20/2023] [Accepted: 04/28/2023] [Indexed: 09/12/2023]
Abstract
Background Assessing the status of malaria transmission in endemic areas becomes increasingly challenging as countries approach elimination. Serology can provide robust estimates of malaria transmission intensities, and multiplex serological assays allow for simultaneous assessment of markers of recent and historical malaria exposure. Methods Here, we evaluated different statistical and machine learning methods for analyzing multiplex malaria-specific antibody response data to classify recent and historical exposure to Plasmodium falciparum and Plasmodium vivax. To assess these methods, we utilized samples from a health-facility based survey (n = 9132) in the Philippines, where we quantified antibody responses against 8 P. falciparum and 6 P. vivax-specific antigens from 3 sites with varying transmission intensity. Findings Measurements of antibody responses and seroprevalence were consistent with the 3 sites' known endemicity status. Among the models tested, a machine learning (ML) approach (Random Forest model) using 4 serological markers (PfGLURP R2, Etramp5.Ag1, GEXP18, and PfMSP119) gave better predictions for P. falciparum recent infection in Palawan (AUC: 0.9591, CI 0.9497-0.9684) than individual antigen seropositivity. Although the ML approach did not improve P. vivax infection predictions, ML classifications confirmed the absence of recent exposure to P. falciparum and P. vivax in both Occidental Mindoro and Bataan. For predicting historical P. falciparum and P. vivax transmission, seroprevalence and seroconversion rates based on cumulative exposure markers AMA1 and MSP119 showed reliable trends in the 3 sites. Interpretation Our study emphasizes the utility of serological markers in predicting recent and historical exposure in a sub-national elimination setting, and also highlights the potential use of machine learning models using multiplex antibody responses to improve assessment of the malaria transmission status of countries aiming for elimination. This work also provides baseline antibody data for monitoring risk in malaria-endemic areas in the Philippines. Funding Newton Fund, Philippine Council for Health Research and Development, UK Medical Research Council.
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Affiliation(s)
- Maria Lourdes M. Macalinao
- Department of Parasitology and National Reference Laboratory for Malaria and Other Parasites, Research Institute for Tropical Medicine, Department of Health, Muntinlupa City, Philippines
- Faculty of Infectious and Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
| | - Kimberly M. Fornace
- Faculty of Infectious and Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Ralph A. Reyes
- Department of Parasitology and National Reference Laboratory for Malaria and Other Parasites, Research Institute for Tropical Medicine, Department of Health, Muntinlupa City, Philippines
| | - Tom Hall
- Faculty of Infectious and Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alison Paolo N. Bareng
- Department of Parasitology and National Reference Laboratory for Malaria and Other Parasites, Research Institute for Tropical Medicine, Department of Health, Muntinlupa City, Philippines
| | | | - Christèle Huon
- Malaria Parasite Biology and Vaccines Unit, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Chetan E. Chitnis
- Malaria Parasite Biology and Vaccines Unit, Department of Parasites and Insect Vectors, Institut Pasteur, Paris, France
| | - Jennifer S. Luchavez
- Department of Parasitology and National Reference Laboratory for Malaria and Other Parasites, Research Institute for Tropical Medicine, Department of Health, Muntinlupa City, Philippines
| | - Kevin K.A. Tetteh
- Faculty of Infectious and Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Katsuyuki Yui
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Shionogi Global Infectious Diseases Division, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Julius Clemence R. Hafalla
- Faculty of Infectious and Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Fe Esperanza J. Espino
- Department of Parasitology and National Reference Laboratory for Malaria and Other Parasites, Research Institute for Tropical Medicine, Department of Health, Muntinlupa City, Philippines
| | - Chris J. Drakeley
- Faculty of Infectious and Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Naserrudin NA, Lin PYP, Monroe A, Culleton R, Baumann SE, Sato S, Adhikari B, Fornace KM, Hod R, Jeffree MS, Ahmed K, Hassan MR. Exploring barriers to and facilitators of malaria prevention practices: a photovoice study with rural communities at risk to Plasmodium knowlesi malaria in Sabah, Malaysia. BMC Public Health 2023; 23:1316. [PMID: 37430300 DOI: 10.1186/s12889-023-16173-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 06/22/2023] [Indexed: 07/12/2023] Open
Abstract
BACKGROUND The control of Plasmodium knowlesi malaria remains challenging due to the presence of macaque monkeys and predominantly outdoor-biting Anopheles mosquitoes around human settlements. This study aims to explore the barriers and facilitators related to prevention of mosquito bites among rural communities living in Sabah, Malaysia using the participatory visual method, photovoice. METHODS From January through June 2022, 26 participants were recruited from four villages in Kudat, Sabah, using purposive sampling. Participants were male and female villagers, aged > 18 years old. After photovoice training in the villages, participants documented facilitators of and barriers related to avoiding mosquito bites using their own smartphone cameras, and provided narratives for their photos. Twelve Focus Group Discussions (FGDs) sessions in three rounds were held to share and discuss the photos, and to address challenges to the avoidance of mosquito bites. All discussions were conducted in the Sabah Malay dialect, and were video and audio recorded, transcribed, and analyzed using reflexive thematic analysis. The Ideation Model, a meta-theoretical model of behaviour change, underpinned this study. RESULTS The most common types of barriers identified by participants included (I) intrapersonal factors such as low perceived threat of malaria, (II) livelihood and lifestyle activities consisting of the local economy and socio-cultural activities, and (III) physical and social environment. The facilitators were categorized into (I) intrapersonal reasons, including having the opportunity to stay indoors, especially women who are housewives, (II) social support by the households, neaighbours and healthcare workers, and (III) support from healthcare services and malaria awareness program. Participants emphasized the importance of stakeholder's support in implementing feasible and affordable approaches to P. knowlesi malaria control. CONCLUSION Results provided insights regarding the challenges to preventing P. knowlesi malaria in rural Kudat, Sabah. The participation of communities in research was valuable in expanding knowledge of local challenges and highlighting possible ways to overcome barriers. These findings may be used to improve strategies for zoonotic malaria control, which is critical for advancing social change and minimizing health disparities in malaria prevention.
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Affiliation(s)
- Nurul Athirah Naserrudin
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia
- Sabah State Health Department, Ministry of Health, 88590, Kota Kinabalu, Malaysia
| | - Pauline Yong Pau Lin
- Faculty of Social Sciences and Humanities, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - April Monroe
- Johns Hopkins Center for Communication Programs, Baltimore, MD, USA
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, 791-0295, Japan
| | - Sara Elizabeth Baumann
- Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Shigeharu Sato
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Bipin Adhikari
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Kimberly M Fornace
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
| | - Rozita Hod
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia.
| | - Mohammad Saffree Jeffree
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia
- Department of Public Health Medicine, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Kamruddin Ahmed
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia
- Department of Pathology and Microbiology, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, 88400, Kota Kinabalu, Malaysia
| | - Mohd Rohaizat Hassan
- Department of Public Health Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, 56000, Kuala Lumpur, Malaysia.
- Faculty of Medicine and Health Sciences, Borneo Medical and Health Research Centre, Universiti Malaysia, 88400, Sabah, Kota Kinabalu, Malaysia.
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Fornace KM, Topazian HM, Routledge I, Asyraf S, Jelip J, Lindblade KA, Jeffree MS, Ruiz Cuenca P, Bhatt S, Ahmed K, Ghani AC, Drakeley C. No evidence of sustained nonzoonotic Plasmodium knowlesi transmission in Malaysia from modelling malaria case data. Nat Commun 2023; 14:2945. [PMID: 37263994 PMCID: PMC10235043 DOI: 10.1038/s41467-023-38476-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 05/02/2023] [Indexed: 06/03/2023] Open
Abstract
Reported incidence of the zoonotic malaria Plasmodium knowlesi has markedly increased across Southeast Asia and threatens malaria elimination. Nonzoonotic transmission of P. knowlesi has been experimentally demonstrated, but it remains unknown whether nonzoonotic transmission is contributing to increases in P. knowlesi cases. Here, we adapt model-based inference methods to estimate RC, individual case reproductive numbers, for P. knowlesi, P. falciparum and P. vivax human cases in Malaysia from 2012-2020 (n = 32,635). Best fitting models for P. knowlesi showed subcritical transmission (RC < 1) consistent with a large reservoir of unobserved infection sources, indicating P. knowlesi remains a primarily zoonotic infection. In contrast, sustained transmission (RC > 1) was estimated historically for P. falciparum and P. vivax, with declines in RC estimates observed over time consistent with local elimination. Together, this suggests sustained nonzoonotic P. knowlesi transmission is highly unlikely and that new approaches are urgently needed to control spillover risks.
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Affiliation(s)
- Kimberly M Fornace
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, UK.
- Saw Swee Hock School of Public Health, National University of, Singapore, Singapore.
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Hillary M Topazian
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
| | - Isobel Routledge
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
- University of California, San Francisco, San Francisco, USA
| | - Syafie Asyraf
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Jenarun Jelip
- Vector-borne Disease Control Division, Ministry of Health Malaysia, Putrajaya, Malaysia
| | - Kim A Lindblade
- Global Malaria Programme, World Health Organization, Geneva, Switzerland
| | | | - Pablo Ruiz Cuenca
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Samir Bhatt
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
- Section of Epidemiology, University of Copenhagen, Copenhagen, Denmark
| | - Kamruddin Ahmed
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Azra C Ghani
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, London, UK
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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10
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Klim H, William T, Chua TH, Rajahram GS, Drakeley CJ, Carroll MW, Fornace KM. Quantifying human-animal contact rates in Malaysian Borneo: Influence of agricultural landscapes on contact with potential zoonotic disease reservoirs. Front Epidemiol 2023; 2:1057047. [PMID: 38455308 PMCID: PMC10910987 DOI: 10.3389/fepid.2022.1057047] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/28/2022] [Indexed: 03/09/2024]
Abstract
Changing landscapes across the globe, but particularly in Southeast Asia, are pushing humans and animals closer together and may increase the likelihood of zoonotic spillover events. Malaysian Borneo is hypothesized to be at high risk of spillover events due to proximity between reservoir species and humans caused by recent deforestation in the region. However, the relationship between landscape and human-animal contact rates has yet to be quantified. An environmentally stratified cross-sectional survey was conducted in Sabah, Malaysia in 2015, collecting geolocated questionnaire data on potential risk factors for contact with animals for 10,100 individuals. 51% of individuals reported contact with poultry, 46% with NHPs, 30% with bats, and 2% with swine. Generalised linear mixed models identified occupational and demographic factors associated with increased contact with these species, which varied when comparing wildlife to domesticated animals. Reported contact rates with each animal group were integrated with remote sensing-derived environmental data within a Bayesian framework to identify regions with high probabilities of contact with animal reservoirs. We have identified high spatial heterogeneity of contact with animals and clear associations between agricultural practices and high animal rates. This approach will help inform public health campaigns in at-risk populations and can improve pathogen surveillance efforts on Malaysian Borneo. This method can additionally serve as a framework for researchers looking to identify targets for future pathogen detection in a chosen region of study.
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Affiliation(s)
- Hannah Klim
- Wellcome Centre for Human Genetics and Pandemic Sciences Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Future of Humanity Institute, Faculty of Philosophy, University of Oxford, Oxford, United Kingdom
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- Gleneagles Hospital, Kota Kinabalu, Malaysia
- Clinical Research Centre, Queen Elizabeth II Hospital, Kota Kinabalu, Malaysia
| | - Tock H. Chua
- Faculty of Medicine and Health Sciences, University of Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Giri S. Rajahram
- Clinical Research Centre, Queen Elizabeth II Hospital, Kota Kinabalu, Malaysia
| | - Chris J. Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Miles W. Carroll
- Wellcome Centre for Human Genetics and Pandemic Sciences Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Kimberly M. Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
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Fornace KM, Senyonjo L, Martin DL, Gwyn S, Schmidt E, Agyemang D, Marfo B, Addy J, Mensah E, Solomon AW, Bailey R, Drakeley CJ, Pullan RL. Characterising spatial patterns of neglected tropical disease transmission using integrated sero-surveillance in Northern Ghana. PLoS Negl Trop Dis 2022; 16:e0010227. [PMID: 35259153 PMCID: PMC8932554 DOI: 10.1371/journal.pntd.0010227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/18/2022] [Accepted: 02/03/2022] [Indexed: 11/18/2022] Open
Abstract
Background
As prevalence decreases in pre-elimination settings, identifying the spatial distribution of remaining infections to target control measures becomes increasingly challenging. By measuring multiple antibody responses indicative of past exposure to different pathogens, integrated serological surveys enable simultaneous characterisation of residual transmission of multiple pathogens.
Methodology/Principal findings
Here, we combine integrated serological surveys with geostatistical modelling and remote sensing-derived environmental data to estimate the spatial distribution of exposure to multiple diseases in children in Northern Ghana. The study utilised the trachoma surveillance survey platform (cross-sectional two-stage cluster-sampled surveys) to collect information on additional identified diseases at different stages of elimination with minimal additional cost. Geostatistical modelling of serological data allowed identification of areas with high probabilities of recent exposure to diseases of interest, including areas previously unknown to control programmes. We additionally demonstrate how serological surveys can be used to identify areas with exposure to multiple diseases and to prioritise areas with high uncertainty for future surveys. Modelled estimates of cluster-level prevalence were strongly correlated with more operationally feasible metrics of antibody responses.
Conclusions/Significance
This study demonstrates the potential of integrated serological surveillance to characterise spatial distributions of exposure to multiple pathogens in low transmission and elimination settings when the probability of detecting infections is low.
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Affiliation(s)
- Kimberly M. Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
| | - Laura Senyonjo
- Research Team, Sightsavers UK, Haywards Heath, United Kingdom
| | - Diana L. Martin
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Sarah Gwyn
- Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Elena Schmidt
- Research Team, Sightsavers UK, Haywards Heath, United Kingdom
| | | | - Benjamin Marfo
- Neglected Tropical Disease Team, Ghana Health Service, Accra, Ghana
| | - James Addy
- Neglected Tropical Disease Team, Ghana Health Service, Accra, Ghana
| | | | - Anthony W. Solomon
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland
| | - Robin Bailey
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Chris J. Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Rachel L. Pullan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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12
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Chan YL, Patterson CL, Priest JW, Stresman G, William T, Chua TH, Tetteh K, Lammie P, Drakeley C, Fornace KM. Assessing seroprevalence and associated risk factors for multiple infectious diseases in Sabah, Malaysia using serological multiplex bead assays. Front Public Health 2022; 10:924316. [PMID: 36388287 PMCID: PMC9641279 DOI: 10.3389/fpubh.2022.924316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 10/07/2022] [Indexed: 01/24/2023] Open
Abstract
Background Infectious diseases continue to burden populations in Malaysia, especially among rural communities where resources are limited and access to health care is difficult. Current epidemiological trends of several neglected tropical diseases in these populations are at present absent due to the lack of habitual and efficient surveillance. To date, various studies have explored the utility of serological multiplex beads to monitor numerous diseases simultaneously. We therefore applied this platform to assess population level exposure to six infectious diseases in Sabah, Malaysia. Furthermore, we concurrently investigated demographic and spatial risk factors that may be associated with exposure for each disease. Methods This study was conducted in four districts of Northern Sabah in Malaysian Borneo, using an environmentally stratified, population-based cross-sectional serological survey targeted to determine risk factors for malaria. Samples were collected between September to December 2015, from 919 villages totaling 10,100 persons. IgG responses to twelve antigens of six diseases (lymphatic filariasis- Bm33, Bm14, BmR1, Wb123; strongyloides- NIE; toxoplasmosis-SAG2A; yaws- Rp17 and TmpA; trachoma- Pgp3, Ct694; and giardiasis- VSP3, VSP5) were measured using serological multiplex bead assays. Eight demographic risk factors and twelve environmental covariates were included in this study to better understand transmission in this community. Results Seroprevalence of LF antigens included Bm33 (10.9%), Bm14+ BmR1 (3.5%), and Wb123 (1.7%). Seroprevalence of Strongyloides antigen NIE was 16.8%, for Toxoplasma antigen SAG2A was 29.9%, and Giardia antigens GVSP3 + GVSP5 was 23.2%. Seroprevalence estimates for yaws Rp17 was 4.91%, for TmpA was 4.81%, and for combined seropositivity to both antigens was 1.2%. Seroprevalence estimates for trachoma Pgp3 + Ct694 were 4.5%. Age was a significant risk factors consistent among all antigens assessed, while other risk factors varied among the different antigens. Spatial heterogeneity of seroprevalence was observed more prominently in lymphatic filariasis and toxoplasmosis. Conclusions Multiplex bead assays can be used to assess serological responses to numerous pathogens simultaneously to support infectious disease surveillance in rural communities, especially where prevalences estimates are lacking for neglected tropical diseases. Demographic and spatial data collected alongside serosurveys can prove useful in identifying risk factors associated with exposure and geographic distribution of transmission.
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Affiliation(s)
- YuYen L. Chan
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
- *Correspondence: YuYen L. Chan
| | - Catriona L. Patterson
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jeffrey W. Priest
- Division of Foodborne, Waterborne, and Environmental Diseases, United States Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Gillian Stresman
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Tock H. Chua
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Kevin Tetteh
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Patrick Lammie
- Division of Parasitic Diseases and Malaria, United States Centers for Disease Control and Prevention, Atlanta, GA, United States
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kimberly M. Fornace
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
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13
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Malijan RPB, Mechan F, Braganza JC, Valle KMR, Salazar FV, Torno MM, Aure WE, Bacay BA, Espino FE, Torr SJ, Fornace KM, Drakeley C, Ferguson HM. The seasonal dynamics and biting behavior of potential Anopheles vectors of Plasmodium knowlesi in Palawan, Philippines. Parasit Vectors 2021; 14:357. [PMID: 34233742 PMCID: PMC8261946 DOI: 10.1186/s13071-021-04853-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 06/17/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A small number of human cases of the zoonotic malaria Plasmodium knowlesi have been reported in Palawan Island, the Philippines. Identification of potential vector species and their bionomics is crucial for understanding human exposure risk in this setting. Here, we combined longitudinal surveillance with a trap-evaluation study to address knowledge gaps about the ecology and potential for zoonotic spillover of this macaque malaria in Palawan Island. METHODS The abundance, diversity and biting behavior of human-biting Anopheles mosquitoes were assessed through monthly outdoor human landing catches (HLC) in three ecotypes representing different land use (forest edge, forest and agricultural area) across 8 months. Additionally, the host preference and biting activity of potential Anopheles vectors were assessed through comparison of their abundance and capture time in traps baited with humans (HLC, human-baited electrocuting net-HEN) or macaques (monkey-baited trap-MBT, monkey-baited electrocuting net-MEN). All female Anopheles mosquitoes were tested for the presence of Plasmodium parasites by PCR. RESULTS Previously incriminated vectors Anopheles balabacensis and An. flavirostris accounted for > 95% of anophelines caught in longitudinal surveillance. However, human biting densities were relatively low (An. balabacensis: 0.34-1.20 per night, An. flavirostris: 0-2 bites per night). Biting densities of An. balabacensis were highest in the forest edge, while An. flavirostris was most abundant in the agricultural area. The abundance of An. balabacensis and An. flavirostris was significantly higher in HLC than in MBT. None of the 357 female Anopheles mosquitoes tested for Plasmodium infection were positive. CONCLUSIONS The relatively low density and lack of malaria infection in Anopheles mosquitoes sampled here indicates that exposure to P. knowlesi in this setting is considerably lower than in neighboring countries (i.e. Malaysia), where it is now the primary cause of malaria in humans. Although anophelines had lower abundance in MBTs than in HLCs, An. balabacensis and An. flavirostris were caught by both methods, suggesting they could act as bridge vectors between humans and macaques. These species bite primarily outdoors during the early evening, confirming that insecticide-treated nets are unlikely to provide protection against P. knowlesi vectors.
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Affiliation(s)
- Richard Paul B Malijan
- Department of Medical Entomology, Research Institute for Tropical Medicine, Alabang, 1781, Muntinlupa City, Metro Manila, Philippines
| | - Frank Mechan
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5Q4, UK
| | - Jessie C Braganza
- Department of Medical Entomology, Research Institute for Tropical Medicine, Alabang, 1781, Muntinlupa City, Metro Manila, Philippines
| | - Kristelle Mae R Valle
- Department of Medical Entomology, Research Institute for Tropical Medicine, Alabang, 1781, Muntinlupa City, Metro Manila, Philippines
| | - Ferdinand V Salazar
- Department of Medical Entomology, Research Institute for Tropical Medicine, Alabang, 1781, Muntinlupa City, Metro Manila, Philippines
| | - Majhalia M Torno
- Department of Medical Entomology, Research Institute for Tropical Medicine, Alabang, 1781, Muntinlupa City, Metro Manila, Philippines.,Taxonomy & Pesticide Efficacy Branch, Vector Biology & Control Division, Environment Health Institute, National Environment Agency, Ministry of Sustainability and the Environment, 11 Biopolis Way, Singapore, 138667, Singapore
| | - Wilfredo E Aure
- Department of Medical Entomology, Research Institute for Tropical Medicine, Alabang, 1781, Muntinlupa City, Metro Manila, Philippines
| | - Brian A Bacay
- Department of Medical Entomology, Research Institute for Tropical Medicine, Alabang, 1781, Muntinlupa City, Metro Manila, Philippines
| | - Fe Esperanza Espino
- Department of Parasitology, Research Institute for Tropical Medicine, Alabang, 1781, Muntinlupa City, Ma, Metro Manila, Philippines
| | - Stephen J Torr
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, L3 5Q4, UK
| | - Kimberly M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Tropical Medicine and Hygiene, London, WC1E 7HT, UK
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Tropical Medicine and Hygiene, London, WC1E 7HT, UK
| | - Heather M Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK.
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14
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Byrne I, Aure W, Manin BO, Vythilingam I, Ferguson HM, Drakeley CJ, Chua TH, Fornace KM. Environmental and spatial risk factors for the larval habitats of Plasmodium knowlesi vectors in Sabah, Malaysian Borneo. Sci Rep 2021; 11:11810. [PMID: 34083582 PMCID: PMC8175559 DOI: 10.1038/s41598-021-90893-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 05/18/2021] [Indexed: 12/22/2022] Open
Abstract
Land-use changes, such as deforestation and agriculture, can influence mosquito vector populations and malaria transmission. These land-use changes have been linked to increased incidence in human cases of the zoonotic malaria Plasmodium knowlesi in Sabah, Malaysian Borneo. This study investigates whether these associations are partially driven by fine-scale land-use changes creating more favourable aquatic breeding habitats for P. knowlesi anopheline vectors. Using aerial remote sensing data, we developed a sampling frame representative of all land use types within a major focus of P. knowlesi transmission. From 2015 to 2016 monthly longitudinal surveys of larval habitats were collected in randomly selected areas stratified by land use type. Additional remote sensing data on environmental variables, land cover and landscape configuration were assembled for the study site. Risk factor analyses were performed over multiple spatial scales to determine associations between environmental and spatial variables and anopheline larval presence. Habitat fragmentation (300 m), aspect (350 m), distance to rubber plantations (100 m) and Culex larval presence were identified as risk factors for Anopheles breeding. Additionally, models were fit to determine the presence of potential larval habitats within the areas surveyed and used to generate a time-series of monthly predictive maps. These results indicate that land-use change and topography influence the suitability of larval habitats, and may partially explain the link between P. knowlesi incidence and deforestation. The predictive maps, and identification of the spatial scales at which risk factors are most influential may aid spatio-temporally targeted vector control interventions.
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Affiliation(s)
- Isabel Byrne
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK.
| | - Wilfredo Aure
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
- Research Institute for Tropical Medicine, Manila, Philippines
| | - Benny O Manin
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Heather M Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK
| | - Tock H Chua
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Kimberly M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, Bloomsbury, London, WCIE 7HT, UK
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Abstract
Land use and land cover changes, such as deforestation, agricultural expansion and urbanization, are one of the largest anthropogenic environmental changes globally. Recent initiatives to evaluate the feasibility of malaria eradication have highlighted impacts of landscape changes on malaria transmission and the potential of these changes to undermine malaria control and elimination efforts. Multisectoral approaches are needed to detect and minimize negative impacts of land use and land cover changes on malaria transmission while supporting development aiding malaria control, elimination and ultimately eradication. Pathways through which land use and land cover changes disrupt social and ecological systems to increase or decrease malaria risks are outlined, identifying priorities and opportunities for a global malaria eradication campaign. The impacts of land use and land cover changes on malaria transmission are complex and highly context-specific, with effects changing over time and space. Landscape changes are only one element of a complex development process with wider economic and social dimensions affecting human health and wellbeing. While deforestation and other landscape changes threaten to undermine malaria control efforts and have driven the emergence of zoonotic malaria, most of the malaria elimination successes have been underpinned by agricultural development and land management. Malaria eradication is not feasible without addressing these changing risks while, conversely, consideration of malaria impacts in land management decisions has the potential to significantly accelerate progress towards eradication. Multisectoral cooperation and approaches to linking malaria control and environmental science, such as conducting locally relevant ecological monitoring, integrating landscape data into malaria surveillance systems and designing environmental management strategies to reduce malaria burdens, are essential to achieve malaria eradication.
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Affiliation(s)
- Kimberly M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK. .,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK.
| | - Adriana V Diaz
- Pathology and Population Sciences, Royal Veterinary College, Hatfield, UK
| | - Jo Lines
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, UK
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16
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Reyes RA, Fornace KM, Macalinao MLM, Boncayao BL, De La Fuente ES, Sabanal HM, Bareng APN, Medado IAP, Mercado ES, Baquilod MS, Luchavez JS, Hafalla JCR, Drakeley CJ, Espino FEJ. Enhanced Health Facility Surveys to Support Malaria Control and Elimination across Different Transmission Settings in the Philippines. Am J Trop Med Hyg 2021; 104:968-978. [PMID: 33534761 PMCID: PMC7941801 DOI: 10.4269/ajtmh.20-0814] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/15/2020] [Indexed: 12/12/2022] Open
Abstract
Following substantial progress in malaria control in the Philippines, new surveillance approaches are needed to identify and target residual malaria transmission. This study evaluated an enhanced surveillance approach using rolling cross-sectional surveys of all health facility attendees augmented with molecular diagnostics and geolocation. Facility surveys were carried out in three sites representing different transmission intensities: Morong, Bataan (pre-elimination), Abra de Ilog, Occidental Mindoro (stable medium risk), and Rizal, Palawan (high risk, control). Only one rapid diagnostic test (RDT)–positive infection and no PCR confirmed infections were found in Bataan and Occidental Mindoro, suggesting the absence of transmission. In Palawan, the inclusion of all health facility attendees, regardless of symptoms, and use of molecular diagnostics identified 313 infected individuals in addition to 300 cases identified by routine screening of febrile patients with the RDT or microscopy. Of these, the majority (313/613) were subpatent infections and only detected using molecular methods. Simultaneous collection of GPS coordinates on tablet-based applications allowed real-time mapping of malaria infections. Risk factor analysis showed higher risks in children and indigenous groups, with bed net use having a protective effect. Subpatent infections were more common in men and older age-groups. Overall, malaria risks were not associated with participants’ classification, and some of the non-patient clinic attendees reported febrile illnesses (1.9%, 26/1,369), despite not seeking treatment, highlighting the widespread distribution of infection in communities. Together, these data illustrate the utility of health facility–based surveys to augment surveillance data to increase the probability of detecting infections in the wider community.
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Affiliation(s)
- Ralph A Reyes
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Kimberly M Fornace
- 2Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Beaulah L Boncayao
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Ellaine S De La Fuente
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Hennessey M Sabanal
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Alison Paolo N Bareng
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Inez Andrea P Medado
- 3Molecular Biology Laboratory, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Edelwisa S Mercado
- 3Molecular Biology Laboratory, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Mario S Baquilod
- 4Department of Health, MIMAROPA Center for Health Development, Quirino Memorial Medical Center Compound, Quezon, Philippines
| | - Jennifer S Luchavez
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
| | - Julius Clemence R Hafalla
- 2Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris J Drakeley
- 2Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Fe Esperanza J Espino
- 1Department of Parasitology, Research Institute for Tropical Medicine, Muntinlupa, Philippines
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17
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Fornace KM, Fronterrè C, Fleming FM, Simpson H, Zoure H, Rebollo M, Mwinzi P, Vounatsou P, Pullan RL. Evaluating survey designs for targeting preventive chemotherapy against Schistosoma haematobium and Schistosoma mansoni across sub-Saharan Africa: a geostatistical analysis and modelling study. Parasit Vectors 2020; 13:555. [PMID: 33203463 PMCID: PMC7672864 DOI: 10.1186/s13071-020-04413-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/21/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Schistosomiasis control programmes primarily use school-based surveys to identify areas for mass drug administration of preventive chemotherapy. However, as the spatial distribution of schistosomiasis can be highly focal, transmission may not be detected by surveys implemented at districts or larger spatial units. Improved mapping strategies are required to accurately and cost-effectively target preventive chemotherapy to remaining foci across all possible spatial distributions of schistosomiasis. METHODS Here, we use geostatistical models to quantify the spatial heterogeneity of Schistosoma haematobium and S. mansoni across sub-Saharan Africa using the most comprehensive dataset available on school-based surveys. Applying this information to parameterise simulations, we assess the accuracy and cost of targeting alternative implementation unit sizes across the range of plausible schistosomiasis distributions. We evaluate the consequences of decisions based on survey designs implemented at district and subdistrict levels sampling different numbers of schools. Cost data were obtained from field surveys conducted across multiple countries and years, with cost effectiveness evaluated as the cost per correctly identified school. RESULTS Models identified marked differences in prevalence and spatial distributions between countries and species; however, results suggest implementing surveys at subdistrict level increase the accuracy of treatment classifications across most scenarios. While sampling intensively at the subdistrict level resulted in the highest classification accuracy, this sampling strategy resulted in the highest costs. Alternatively, sampling the same numbers of schools currently recommended at the district level but stratifying by subdistrict increased cost effectiveness. CONCLUSIONS This study provides a new tool to evaluate schistosomiasis survey designs across a range of transmission settings. Results highlight the importance of considering spatial structure when designing sampling strategies, illustrating that a substantial proportion of children may be undertreated even when an implementation unit is correctly classified. Control programmes need to weigh the increased accuracy of more detailed mapping strategies against the survey costs and treatment priorities.
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Affiliation(s)
- Kimberly M Fornace
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.
| | - Claudio Fronterrè
- Centre for Health Informatics, Computing and Statistics (CHICAS), Lancaster University, Lancaster, UK
| | | | - Hope Simpson
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Honorat Zoure
- Expanded Special Project of the Elimination of Neglected Tropical Diseases (ESPEN), Africa Regional Office of the World Health Organisation, Brazzaville, Congo
| | - Maria Rebollo
- Expanded Special Project of the Elimination of Neglected Tropical Diseases (ESPEN), Africa Regional Office of the World Health Organisation, Brazzaville, Congo
| | - Pauline Mwinzi
- Expanded Special Project of the Elimination of Neglected Tropical Diseases (ESPEN), Africa Regional Office of the World Health Organisation, Brazzaville, Congo
| | | | - Rachel L Pullan
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
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18
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Jumail A, Liew TS, Salgado-Lynn M, Fornace KM, Stark DJ. A comparative evaluation of thermal camera and visual counting methods for primate census in a riparian forest at the Lower Kinabatangan Wildlife Sanctuary (LKWS), Malaysian Borneo. Primates 2020; 62:143-151. [PMID: 32572697 DOI: 10.1007/s10329-020-00837-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 06/12/2020] [Indexed: 10/24/2022]
Abstract
A number of primate census techniques have been developed over the past half-century, each of which have advantages and disadvantages in terms of resources required by researchers (e.g., time and costs), availability of technologies, and effectiveness in different habitat types. This study aims to explore the effectiveness of a thermal imaging technique to estimate the group size of different primate species populations in a degraded riparian forest in the Lower Kinabatangan Wildlife Sanctuary (LKWS), Sabah. We compared this survey technique to the conventional visual counting method along the riverbank. For 38 days, a total of 138 primate groups were observed by thermal camera and visually throughout the study. Optimal conditions for the thermal camera were clear weather, not more than 100 m distance from the observer to the targeted area, boat speed ranging between 5 and 12 km/h, and early morning between 04:30 and 05:30 am. The limitations of the thermal cameras include the inability to identify individual species, sexes, age classes, and also to discern between animals closely aggregated (i.e., mothers with attached infants). Despite these limitations with the thermal camera technique, 1.78 times more primates were detected than counting by eye (p < 0.001), showing the potential benefit of using thermal cameras as an important tool in primate surveys. Nevertheless, ground truthing must be conducted immediately after, or simultaneously during, the thermal survey to verify the species of animals observed on the thermal imagery.
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Affiliation(s)
- Amaziasizamoria Jumail
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia. .,Danau Girang Field Centre, c/o Sabah Wildlife Department, Wisma MUIS, Block B 5th Floor, 88100, Kota Kinabalu, Sabah, Malaysia.
| | - Thor-Seng Liew
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Jalan UMS, 88400, Kota Kinabalu, Sabah, Malaysia
| | - Milena Salgado-Lynn
- Danau Girang Field Centre, c/o Sabah Wildlife Department, Wisma MUIS, Block B 5th Floor, 88100, Kota Kinabalu, Sabah, Malaysia.,School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK.,Sustainable Places Research Institute, Cardiff University, Cardiff, CF10 3BA, UK
| | - Kimberly M Fornace
- London School of Hygiene and Tropical Medicine, Keppel St, Bloomsbury, London, WC1E 7HT, UK
| | - Danica J Stark
- Danau Girang Field Centre, c/o Sabah Wildlife Department, Wisma MUIS, Block B 5th Floor, 88100, Kota Kinabalu, Sabah, Malaysia
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19
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Grignard L, Shah S, Chua TH, William T, Drakeley CJ, Fornace KM. Natural Human Infections With Plasmodium cynomolgi and Other Malaria Species in an Elimination Setting in Sabah, Malaysia. J Infect Dis 2020; 220:1946-1949. [PMID: 31418017 PMCID: PMC6834065 DOI: 10.1093/infdis/jiz397] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 07/31/2019] [Indexed: 12/26/2022] Open
Abstract
To determine the presence and species composition of malaria infections, we screened a subset of samples collected during a cross-sectional survey in Northern Sabah, Malaysia using highly sensitive molecular techniques. Results identified 54 asymptomatic submicroscopic malaria infections, including a large cluster of Plasmodium falciparum and 3 P. knowlesi infections. We additionally identified 2 monoinfections with the zoonotic malaria Plasmodium cynomolgi, both in individuals reporting no history of forest activities or contact with macaques. Results highlight the need for improved surveillance strategies to detect these infections and determine public health impacts.
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Affiliation(s)
- Lynn Grignard
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Sonal Shah
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Tock H Chua
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit.,Gleneagles Hospital, Kota Kinabalu, Malaysia
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kimberly M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.,Centre for Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
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20
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Stark DJ, Fornace KM, Brock PM, Abidin TR, Gilhooly L, Jalius C, Goossens B, Drakeley CJ, Salgado-Lynn M. Long-Tailed Macaque Response to Deforestation in a Plasmodium knowlesi-Endemic Area. Ecohealth 2019; 16:638-646. [PMID: 30927165 PMCID: PMC6910895 DOI: 10.1007/s10393-019-01403-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 01/11/2019] [Accepted: 01/22/2019] [Indexed: 06/01/2023]
Abstract
Land-use changes can impact infectious disease transmission by increasing spatial overlap between people and wildlife disease reservoirs. In Malaysian Borneo, increases in human infections by the zoonotic malaria Plasmodium knowlesi are hypothesised to be due to increasing contact between people and macaques due to deforestation. To explore how macaque responses to environmental change impact disease risks, we analysed movement of a GPS-collared long-tailed macaque in a knowlesi-endemic area in Sabah, Malaysia, during a deforestation event. Land-cover maps were derived from satellite-based and aerial remote sensing data and models of macaque occurrence were developed to evaluate how macaque habitat use was influenced by land-use change. During deforestation, changes were observed in macaque troop home range size, movement speeds and use of different habitat types. Results of models were consistent with the hypothesis that macaque ranging behaviour is disturbed by deforestation events but begins to equilibrate after seeking and occupying a new habitat, potentially impacting human disease risks. Further research is required to explore how these changes in macaque movement affect knowlesi epidemiology on a wider spatial scale.
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Affiliation(s)
- Danica J. Stark
- Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX UK
- Danau Girang Field Centre, c/o Sabah Wildlife Department, Wisma Muis Block B Floor 5, 88100 Kota Kinabalu, Sabah Malaysia
| | - Kimberly M. Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Patrick M. Brock
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G61 1QH UK
| | - Tommy Rowel Abidin
- Infectious Diseases Society Kota Kinabalu- Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Lauren Gilhooly
- Department of Anthropology, Faculty of Social Sciences, University of Western Ontario, Social Science Building, London, N6A 3K7 Canada
| | - Cyrlen Jalius
- Danau Girang Field Centre, c/o Sabah Wildlife Department, Wisma Muis Block B Floor 5, 88100 Kota Kinabalu, Sabah Malaysia
- Wildlife Health, Genetic and Forensic Laboratory, Sabah Wildlife Department, Wisma Muis, 88100 Kota Kinabalu, Sabah Malaysia
| | - Benoit Goossens
- Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX UK
- Danau Girang Field Centre, c/o Sabah Wildlife Department, Wisma Muis Block B Floor 5, 88100 Kota Kinabalu, Sabah Malaysia
- Sabah Wildlife Department, Wisma Muis, 88100 Kota Kinabalu, Sabah Malaysia
- Sustainable Places Research Institute, Cardiff University, 33 Park Place, Cardiff, CF10 3BA UK
| | - Chris J. Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Milena Salgado-Lynn
- Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX UK
- Danau Girang Field Centre, c/o Sabah Wildlife Department, Wisma Muis Block B Floor 5, 88100 Kota Kinabalu, Sabah Malaysia
- Wildlife Health, Genetic and Forensic Laboratory, Sabah Wildlife Department, Wisma Muis, 88100 Kota Kinabalu, Sabah Malaysia
- Sustainable Places Research Institute, Cardiff University, 33 Park Place, Cardiff, CF10 3BA UK
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21
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Fornace KM, Alexander N, Abidin TR, Brock PM, Chua TH, Vythilingam I, Ferguson HM, Manin BO, Wong ML, Ng SH, Cox J, Drakeley C. Local human movement patterns and land use impact exposure to zoonotic malaria in Malaysian Borneo. eLife 2019; 8:47602. [PMID: 31638575 PMCID: PMC6814363 DOI: 10.7554/elife.47602] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 10/15/2019] [Indexed: 01/02/2023] Open
Abstract
Human movement into insect vector and wildlife reservoir habitats determines zoonotic disease risks; however, few data are available to quantify the impact of land use on pathogen transmission. Here, we utilise GPS tracking devices and novel applications of ecological methods to develop fine-scale models of human space use relative to land cover to assess exposure to the zoonotic malaria Plasmodium knowlesi in Malaysian Borneo. Combining data with spatially explicit models of mosquito biting rates, we demonstrate the role of individual heterogeneities in local space use in disease exposure. At a community level, our data indicate that areas close to both secondary forest and houses have the highest probability of human P. knowlesi exposure, providing quantitative evidence for the importance of ecotones. Despite higher biting rates in forests, incorporating human movement and space use into exposure estimates illustrates the importance of intensified interactions between pathogens, insect vectors and people around habitat edges.
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Affiliation(s)
- Kimberly M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom.,Centre on Climate Change and Planetary Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Neal Alexander
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Tommy R Abidin
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Paddy M Brock
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Tock H Chua
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Indra Vythilingam
- Parasitology Department, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Heather M Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Benny O Manin
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Meng L Wong
- Parasitology Department, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sui H Ng
- Department of Pathobiology and Medical Diagnostics, Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Jon Cox
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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22
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Fornace KM, Brock PM, Abidin TR, Grignard L, Herman LS, Chua TH, Daim S, William T, Patterson CLEB, Hall T, Grigg MJ, Anstey NM, Tetteh KKA, Cox J, Drakeley CJ. Environmental risk factors and exposure to the zoonotic malaria parasite Plasmodium knowlesi across northern Sabah, Malaysia: a population-based cross-sectional survey. Lancet Planet Health 2019; 3:e179-e186. [PMID: 31029229 PMCID: PMC6484808 DOI: 10.1016/s2542-5196(19)30045-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/25/2019] [Accepted: 03/01/2019] [Indexed: 06/01/2023]
Abstract
BACKGROUND Land use changes disrupt ecosystems, altering the transmission of vector-borne diseases. These changes have been associated with increasing incidence of zoonotic malaria caused by Plasmodium knowlesi; however, the population-level distributions of infection and exposure remain unknown. We aimed to measure prevalence of serological exposure to P knowlesi and assess associated risk factors. METHODS We did an environmentally stratified, population-based, cross-sectional survey across households in the Kudat, Kota Marudu, Pitas, and Ranau districts in northern Sabah, Malaysia, encompassing a range of ecologies. Using blood samples, the transmission intensity of P knowlesi and other malaria species was measured by specific antibody prevalence and infection detected using molecular methods. Proportions and configurations of land types were extracted from maps derived from satellite images; a data-mining approach was used to select variables. A Bayesian hierarchical model for P knowlesi seropositivity was developed, incorporating questionnaire data about individual and household-level risk factors with selected landscape factors. FINDINGS Between Sept 17, 2015, and Dec 12, 2015, 10 100 individuals with a median age of 25 years (range 3 months to 105 years) were sampled from 2849 households in 180 villages. 5·1% (95% CI 4·8-5·4) were seropositive for P knowlesi, and marked historical decreases were observed in the transmission of Plasmodium falciparum and Plasmodium vivax. Nine Plasmodium spp infections were detected. Age, male sex, contact with macaques, forest use, and raised house construction were positively associated with P knowlesi exposure, whereas residing at higher geographical elevations and use of insecticide were protective. Agricultural and forest variables, such as proportions and fragmentation of land cover types, predicted exposure at different spatial scales from households. INTERPRETATION Although few infections were detected, P knowlesi exposure was observed in all demographic groups and was associated with occupational factors. Results suggest that agricultural expansion and forest fragmentation affect P knowlesi exposure, supporting linkages between land use change and P knowlesi transmission. FUNDING UK Medical Research Council, Natural Environment Research Council, Economic and Social Research Council, and Biotechnology and Biosciences Research Council.
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Affiliation(s)
- Kimberly M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK.
| | - Paddy M Brock
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Tommy R Abidin
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Lynn Grignard
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Lou S Herman
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Tock H Chua
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Sylvia Daim
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia; Gleneagles Hospital, Kota Kinabalu, Malaysia; Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Malaysia
| | - Catriona L E B Patterson
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Tom Hall
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Matthew J Grigg
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia; Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia
| | - Kevin K A Tetteh
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Jonathan Cox
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Chris J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
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23
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Brock PM, Fornace KM, Grigg MJ, Anstey NM, William T, Cox J, Drakeley CJ, Ferguson HM, Kao RR. Predictive analysis across spatial scales links zoonotic malaria to deforestation. Proc Biol Sci 2019; 286:20182351. [PMID: 30963872 PMCID: PMC6367187 DOI: 10.1098/rspb.2018.2351] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/12/2018] [Indexed: 12/15/2022] Open
Abstract
The complex transmission ecologies of vector-borne and zoonotic diseases pose challenges to their control, especially in changing landscapes. Human incidence of zoonotic malaria ( Plasmodium knowlesi) is associated with deforestation although mechanisms are unknown. Here, a novel application of a method for predicting disease occurrence that combines machine learning and statistics is used to identify the key spatial scales that define the relationship between zoonotic malaria cases and environmental change. Using data from satellite imagery, a case-control study, and a cross-sectional survey, predictive models of household-level occurrence of P. knowlesi were fitted with 16 variables summarized at 11 spatial scales simultaneously. The method identified a strong and well-defined peak of predictive influence of the proportion of cleared land within 1 km of households on P. knowlesi occurrence. Aspect (1 and 2 km), slope (0.5 km) and canopy regrowth (0.5 km) were important at small scales. By contrast, fragmentation of deforested areas influenced P. knowlesi occurrence probability most strongly at large scales (4 and 5 km). The identification of these spatial scales narrows the field of plausible mechanisms that connect land use change and P. knowlesi, allowing for the refinement of disease occurrence predictions and the design of spatially-targeted interventions.
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Affiliation(s)
- Patrick M. Brock
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, UK
| | - Kimberly M. Fornace
- London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Matthew J. Grigg
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory 0810, Australia
| | - Nicholas M. Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory 0810, Australia
| | - Timothy William
- Gleneagles Kota Kinabalu Hospital, 88100, Kota Kinabalu, Sabah, Malaysia
- Infectious Diseases Society, Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu 88560, Sabah, Malaysia
| | - Jon Cox
- London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Chris J. Drakeley
- London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Heather M. Ferguson
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, UK
| | - Rowland R. Kao
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G61 1QH, UK
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
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Fornace KM, Herman LS, Abidin TR, Chua TH, Daim S, Lorenzo PJ, Grignard L, Nuin NA, Ying LT, Grigg MJ, William T, Espino F, Cox J, Tetteh KKA, Drakeley CJ. Exposure and infection to Plasmodium knowlesi in case study communities in Northern Sabah, Malaysia and Palawan, The Philippines. PLoS Negl Trop Dis 2018; 12:e0006432. [PMID: 29902171 PMCID: PMC6001952 DOI: 10.1371/journal.pntd.0006432] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/05/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Primarily impacting poor, rural populations, the zoonotic malaria Plasmodium knowlesi is now the main cause of human malaria within Malaysian Borneo. While data is increasingly available on symptomatic cases, little is known about community-level patterns of exposure and infection. Understanding the true burden of disease and associated risk factors within endemic communities is critical for informing evidence-based control measures. METHODOLOGY/PRINCIPAL FINDINGS We conducted comprehensive surveys in three areas where P. knowlesi transmission is reported: Limbuak, Pulau Banggi and Matunggung, Kudat, Sabah, Malaysia and Bacungan, Palawan, the Philippines. Infection prevalence was low with parasites detected by PCR in only 0.2% (4/2503) of the population. P. knowlesi PkSERA3 ag1 antibody responses were detected in 7.1% (95% CI: 6.2-8.2%) of the population, compared with 16.1% (14.6-17.7%) and 12.6% (11.2-14.1%) for P. falciparum and P. vivax. Sero-prevalence was low in individuals <10 years old for P. falciparum and P. vivax consistent with decreased transmission of non-zoonotic malaria species. Results indicated marked heterogeneity in transmission intensity between sites and P. knowlesi exposure was associated with agricultural work (OR 1.63; 95% CI 1.07-2.48) and higher levels of forest cover (OR 2.40; 95% CI 1.29-4.46) and clearing (OR 2.14; 95% CI 1.35-3.40) around houses. Spatial patterns of P. knowlesi exposure differed from exposure to non-zoonotic malaria and P. knowlesi exposed individuals were younger on average than individuals exposed to non-zoonotic malaria. CONCLUSIONS/SIGNIFICANCE This is the first study to describe serological exposure to P. knowlesi and associated risk factors within endemic communities. Results indicate community-level patterns of infection and exposure differ markedly from demographics of reported cases, with higher levels of exposure among women and children. Further work is needed to understand these variations in risk across a wider population and spatial scale.
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Affiliation(s)
- Kimberly M. Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Lou S. Herman
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Tommy R. Abidin
- Infectious Diseases Society Kota Kinabalu- Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
| | - Tock Hing Chua
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Sylvia Daim
- Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Pauline J. Lorenzo
- Research Institute of Tropical Medicine, Department of Health, Muntinlupa City, Philippines
| | - Lynn Grignard
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Nor Afizah Nuin
- Biotechnology Research Institute, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Lau Tiek Ying
- Biotechnology Research Institute, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia
| | - Matthew J. Grigg
- Infectious Diseases Society Kota Kinabalu- Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- Menzies School of Health Research and Charles Darwin University, Darwin, Australia
| | - Timothy William
- Infectious Diseases Society Kota Kinabalu- Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Malaysia
- Jesselton Medical Centre, Kota Kinabalu, Malaysia
| | - Fe Espino
- Research Institute of Tropical Medicine, Department of Health, Muntinlupa City, Philippines
| | - Jonathan Cox
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kevin K. A. Tetteh
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chris J. Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Grigg MJ, Cox J, William T, Jelip J, Fornace KM, Brock PM, von Seidlein L, Barber BE, Anstey NM, Yeo TW, Drakeley CJ. Individual-level factors associated with the risk of acquiring human Plasmodium knowlesi malaria in Malaysia: a case-control study. Lancet Planet Health 2017; 1:e97-e104. [PMID: 28758162 PMCID: PMC5531251 DOI: 10.1016/s2542-5196(17)30031-1] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
BACKGROUND The emergence of human malaria due to the monkey parasite Plasmodium knowlesi threatens elimination efforts in southeast Asia. Changes in land use are thought to be driving the rise in reported P knowlesi cases, but the role of individual-level factors is unclear. To address this knowledge gap we assessed human and environmental factors associated with zoonotic knowlesi malaria risk. METHODS We did this population-based case-control study over a 2 year period in the state of Sabah in Malaysia. We enrolled cases with microscopy-positive, PCR-confirmed malaria who presented to two primary referral hospitals serving the adjacent districts of Kudat and Kota Marudu. We randomly selected three malaria-negative community controls per case, who were matched by village within 2 weeks of case detection. We obtained questionnaire data on demographics, behaviour, and residential malaria risk factors, and we also assessed glucose-6-phosphate dehydrogenase (G6PD) enzyme activity. We used conditional logistic regression models to evaluate exposure risk between P knowlesi cases and controls, and between P knowlesi and human-only Plasmodium spp malaria cases. FINDINGS From Dec 5, 2012, to Jan 30, 2015, we screened 414 patients and subsequently enrolled 229 cases with P knowlesi malaria mono-infection and 91 cases with other Plasmodium spp infection. We enrolled 953 matched controls, including 683 matched to P knowlesi cases and 270 matched to non-P knowlesi cases. Age 15 years or older (adjusted odds ratio [aOR] 4·16, 95% CI 2·09-8·29, p<0·0001), male gender (4·20, 2·54-6·97, p<0·0001), plantation work (3·50, CI, 1·34-9·15, p=0·011), sleeping outside (3·61, 1·48-8·85, p=0·0049), travel (2·48, 1·45-4·23, p=0·0010), being aware of the presence of monkeys in the past 4 weeks (3·35, 1·91-5·88, p<0·0001), and having open eaves or gaps in walls (2·18, 1·33-3·59, p=0·0021) were independently associated with increased risk of symptomatic P knowlesi infection. Farming occupation (aOR 1·89, 95% CI 1·07-3·35, p=0·028), clearing vegetation (1·89, 1·11-3·22, p=0·020), and having long grass around the house (2·08, 1·25-3·46, p=0·0048) increased risk for P knowlesi infection but not other Plasmodium spp infection. G6PD deficiency seemed to be protective against P knowlesi (aOR 0·20, 95% CI 0·04-0·96, p=0·045), as did residual insecticide spraying of household walls (0·52, 0·31-0·87, p=0·014), with the presence of young sparse forest (0·35, 0·20-0·63, p=00040) and rice paddy around the house (0·16, 0·03-0·78, 0·023) also associated with decreased risk. INTERPRETATION Adult men working in agricultural areas were at highest risk of knowlesi malaria, although peri-domestic transmission also occurrs. Human behavioural factors associated with P knowlesi transmission could be targeted in future public health interventions. FUNDING United Kingdom Medical Research Council, Natural Environment Research Council, Economic and Social Research Council, and Biotechnology and Biosciences Research Council.
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Affiliation(s)
- Matthew J Grigg
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia; Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Jonathan Cox
- London School of Hygiene & Tropical Medicine, London, UK
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia; Jesselton Medical Centre, Kota Kinabalu, Sabah, Malaysia; Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia
| | - Jenarun Jelip
- Sabah Department of Health, Kota Kinabalu, Sabah, Malaysia
| | | | - Patrick M Brock
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | | | - Bridget E Barber
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia; Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia; Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - Tsin W Yeo
- Global and Tropical Health Division, Menzies School of Health Research and Charles Darwin University, Darwin, NT, Australia; Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Communicable Disease Centre, Institute of Infectious Diseases and Epidemiology, Tan Tock Seng Hospital, Singapore
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Fornace KM, Abidin TR, Alexander N, Brock P, Grigg MJ, Murphy A, William T, Menon J, Drakeley CJ, Cox J. Association between Landscape Factors and Spatial Patterns of Plasmodium knowlesi Infections in Sabah, Malaysia. Emerg Infect Dis 2016; 22:201-8. [PMID: 26812373 PMCID: PMC4734530 DOI: 10.3201/eid2202.150656] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The zoonotic malaria species Plasmodium knowlesi has become the main cause of human malaria in Malaysian Borneo. Deforestation and associated environmental and population changes have been hypothesized as main drivers of this apparent emergence. We gathered village-level data for P. knowlesi incidence for the districts of Kudat and Kota Marudu in Sabah state, Malaysia, for 2008-2012. We adjusted malaria records from routine reporting systems to reflect the diagnostic uncertainty of microscopy for P. knowlesi. We also developed negative binomial spatial autoregressive models to assess potential associations between P. knowlesi incidence and environmental variables derived from satellite-based remote-sensing data. Marked spatial heterogeneity in P. knowlesi incidence was observed, and village-level numbers of P. knowlesi cases were positively associated with forest cover and historical forest loss in surrounding areas. These results suggest the likelihood that deforestation and associated environmental changes are key drivers in P. knowlesi transmission in these areas.
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Clark EL, Macdonald SE, Thenmozhi V, Kundu K, Garg R, Kumar S, Ayoade S, Fornace KM, Jatau ID, Moftah A, Nolan MJ, Sudhakar NR, Adebambo AO, Lawal IA, Álvarez Zapata R, Awuni JA, Chapman HD, Karimuribo E, Mugasa CM, Namangala B, Rushton J, Suo X, Thangaraj K, Srinivasa Rao ASR, Tewari AK, Banerjee PS, Dhinakar Raj G, Raman M, Tomley FM, Blake DP. Cryptic Eimeria genotypes are common across the southern but not northern hemisphere. Int J Parasitol 2016; 46:537-44. [PMID: 27368611 PMCID: PMC4978698 DOI: 10.1016/j.ijpara.2016.05.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/20/2016] [Accepted: 05/24/2016] [Indexed: 01/09/2023]
Abstract
The seven Eimeria spp. recognised to infect chickens are present globally. Cryptic Eimeria operational taxonomic units (OTUs) are common in the southern but not northern hemisphere. Parasite population structure appears to vary between Eimeria spp.
The phylum Apicomplexa includes parasites of medical, zoonotic and veterinary significance. Understanding the global distribution and genetic diversity of these protozoa is of fundamental importance for efficient, robust and long-lasting methods of control. Eimeria spp. cause intestinal coccidiosis in all major livestock animals and are the most important parasites of domestic chickens in terms of both economic impact and animal welfare. Despite having significant negative impacts on the efficiency of food production, many fundamental questions relating to the global distribution and genetic variation of Eimeria spp. remain largely unanswered. Here, we provide the broadest map yet of Eimeria occurrence for domestic chickens, confirming that all the known species (Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, Eimeria tenella) are present in all six continents where chickens are found (including 21 countries). Analysis of 248 internal transcribed spacer sequences derived from 17 countries provided evidence of possible allopatric diversity for species such as E. tenella (FST values ⩽0.34) but not E. acervulina and E. mitis, and highlighted a trend towards widespread genetic variance. We found that three genetic variants described previously only in Australia and southern Africa (operational taxonomic units x, y and z) have a wide distribution across the southern, but not the northern hemisphere. While the drivers for such a polarised distribution of these operational taxonomic unit genotypes remains unclear, the occurrence of genetically variant Eimeria may pose a risk to food security and animal welfare in Europe and North America should these parasites spread to the northern hemisphere.
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Affiliation(s)
- Emily L Clark
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, UK
| | - Sarah E Macdonald
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, UK
| | - V Thenmozhi
- Department of Veterinary Parasitology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - Krishnendu Kundu
- Division of Parasitology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Rajat Garg
- Division of Parasitology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Saroj Kumar
- Division of Parasitology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Simeon Ayoade
- Department of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Kimberly M Fornace
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, UK
| | - Isa Danladi Jatau
- Department of Parasitology and Entomology, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria
| | - Abdalgader Moftah
- School of Agriculture, Food and Rural Development, Newcastle University, Newcastle upon Tyne, UK
| | - Matthew J Nolan
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, UK
| | - N R Sudhakar
- Division of Parasitology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - A O Adebambo
- Department of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - I A Lawal
- Department of Parasitology and Entomology, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria
| | - Ramón Álvarez Zapata
- Universidad Central de Venezuela, Facultad de Agronomía Instituto de Producción Animal, Av. Universidad via El Limón, Maracay, Venezuela
| | | | - H David Chapman
- Department of Poultry Science, University of Arkansas, Fayetteville, AR, USA
| | - Esron Karimuribo
- Southern African Centre for Infectious Disease Surveillance, Morogoro, Tanzania
| | - Claire M Mugasa
- Department of Biotechnical and Diagnostic sciences College of Veterinary Medicine, Animal resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Boniface Namangala
- Department of Paraclinical Studies, University of Zambia, Faculty of Veterinary Medicine, Lusaka, Zambia
| | - Jonathan Rushton
- Production and Population Health, Royal Veterinary College, North Mymms, Hertfordshire, UK
| | - Xun Suo
- National Animal Protozoa Laboratory & College of Veterinary Medicine, China Agricultural University, Beijing, China
| | | | | | - Anup K Tewari
- Division of Parasitology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Partha S Banerjee
- Division of Parasitology, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - G Dhinakar Raj
- Department of Animal Biotechnology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - M Raman
- Department of Veterinary Parasitology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - Fiona M Tomley
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, UK
| | - Damer P Blake
- Department of Pathology and Pathogen Biology, Royal Veterinary College, North Mymms, Hertfordshire, UK.
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Fornace KM, Nuin NA, Betson M, Grigg MJ, William T, Anstey NM, Yeo TW, Cox J, Ying LT, Drakeley CJ. Asymptomatic and Submicroscopic Carriage of Plasmodium knowlesi Malaria in Household and Community Members of Clinical Cases in Sabah, Malaysia. J Infect Dis 2015; 213:784-7. [PMID: 26433222 PMCID: PMC4747612 DOI: 10.1093/infdis/jiv475] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 09/22/2015] [Indexed: 11/26/2022] Open
Abstract
Although asymptomatic carriage of human malaria species has been widely reported, the extent of asymptomatic, submicroscopic Plasmodium knowlesi parasitemia is unknown. In this study, samples were obtained from individuals residing in households or villages of symptomatic malaria cases with the aim of detecting submicroscopic P. knowlesi in this population. Four published molecular assays were used to confirm the presence of P. knowlesi. Latent class analysis revealed that the estimated proportion of asymptomatic individuals was 6.9% (95% confidence interval, 5.6%–8.4%). This study confirms the presence of a substantial number of asymptomatic monoinfections across all age groups; further work is needed to estimate prevalence in the wider community.
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Affiliation(s)
| | | | | | - Matthew J Grigg
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit Menzies School of Health Research, Darwin, Australia
| | - Timothy William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit Sabah Department of Health, Clinical Research Centre Jesselton Medical Centre, Kota Kinabalu, Malaysia
| | - Nicholas M Anstey
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit Menzies School of Health Research, Darwin, Australia
| | - Tsin W Yeo
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit Menzies School of Health Research, Darwin, Australia
| | | | - Lau Tiek Ying
- Biotechnology Research Institute, Universiti Sabah Malaysia
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Grigg MJ, William T, Drakeley CJ, Jelip J, von Seidlein L, Barber BE, Fornace KM, Anstey NM, Yeo TW, Cox J. Factors that are associated with the risk of acquiring Plasmodium knowlesi malaria in Sabah, Malaysia: a case-control study protocol. BMJ Open 2014; 4:e006004. [PMID: 25149186 PMCID: PMC4156811 DOI: 10.1136/bmjopen-2014-006004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
INTRODUCTION Plasmodium knowlesi has long been present in Malaysia, and is now an emerging cause of zoonotic human malaria. Cases have been confirmed throughout South-East Asia where the ranges of its natural macaque hosts and Anopheles leucosphyrus group vectors overlap. The majority of cases are from Eastern Malaysia, with increasing total public health notifications despite a concurrent reduction in Plasmodium falciparum and P. vivax malaria. The public health implications are concerning given P. knowlesi has the highest risk of severe and fatal disease of all Plasmodium spp in Malaysia. Current patterns of risk and disease vary based on vector type and competence, with individual exposure risks related to forest and forest-edge activities still poorly defined. Clustering of cases has not yet been systematically evaluated despite reports of peri-domestic transmission and known vector competence for human-to-human transmission. METHODS AND ANALYSIS A population-based case-control study will be conducted over a 2-year period at two adjacent districts in north-west Sabah, Malaysia. Confirmed malaria cases presenting to the district hospital sites meeting relevant inclusion criteria will be requested to enrol. Three community controls matched to the same village as the case will be selected randomly. Study procedures will include blood sampling and administration of household and individual questionnaires to evaluate potential exposure risks associated with acquisition of P. knowlesi malaria. Secondary outcomes will include differences in exposure variables between P. knowlesi and other Plasmodium spp, risk of severe P. knowlesi malaria, and evaluation of P. knowlesi case clustering. Primary analysis will be per protocol, with adjusted ORs for exposure risks between cases and controls calculated using conditional multiple logistic regression models. ETHICS This study has been approved by the human research ethics committees of Malaysia, the Menzies School of Health Research, Australia, and the London School of Hygiene and Tropical Medicine, UK.
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Affiliation(s)
- M J Grigg
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - T William
- Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia Infectious Diseases Unit, Clinical Research Centre, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, Malaysia Sabah Department of Health, Kota Kinabalu, Sabah, Malaysia
| | - C J Drakeley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - J Jelip
- Sabah Department of Health, Kota Kinabalu, Sabah, Malaysia
| | - L von Seidlein
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia
| | - B E Barber
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia
| | - K M Fornace
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - N M Anstey
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - T W Yeo
- Menzies School of Health Research and Charles Darwin University, Darwin, Northern Territory, Australia Infectious Diseases Society Sabah-Menzies School of Health Research Clinical Research Unit, Kota Kinabalu, Sabah, Malaysia Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - J Cox
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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Fornace KM, Clark EL, Macdonald SE, Namangala B, Karimuribo E, Awuni JA, Thieme O, Blake DP, Rushton J. Occurrence of Eimeria species parasites on small-scale commercial chicken farms in Africa and indication of economic profitability. PLoS One 2013; 8:e84254. [PMID: 24391923 PMCID: PMC3877271 DOI: 10.1371/journal.pone.0084254] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 11/13/2013] [Indexed: 11/21/2022] Open
Abstract
Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa.
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Affiliation(s)
| | - Emily L. Clark
- Royal Veterinary College, North Mymms, Hertfordshire, United Kingdom
| | | | - Boniface Namangala
- Department of Paraclinical Studies, University of Zambia, Faculty of Veterinary Medicine, Lusaka, Zambia
| | - Esron Karimuribo
- Southern African Centre for Infectious Disease Surveillance, Morogoro, Tanzania
| | | | - Olaf Thieme
- Food and Agriculture Organization, Rome, Italy
| | - Damer P. Blake
- Royal Veterinary College, North Mymms, Hertfordshire, United Kingdom
| | - Jonathan Rushton
- Royal Veterinary College, North Mymms, Hertfordshire, United Kingdom
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Cunliffe HE, Jiang Y, Fornace KM, Yang F, Meltzer PS. PAR6B is required for tight junction formation and activated PKCζ localization in breast cancer. Am J Cancer Res 2012; 2:478-491. [PMID: 22957302 PMCID: PMC3433109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 07/11/2012] [Indexed: 06/01/2023] Open
Abstract
Dysregulation of mechanisms that govern the control of epithelial cell polarity, morphology and plasticity are emerging as key processes in tumor progression. In this study we report amplification and overexpression of PAR6B, an essential component in epithelial cell tight junction (TJ) formation and maintenance of apico-basal polarity, in breast cancer cell lines. Analysis of chromosome 20q13.13 in 11 breast cancer cell lines by fluorescence in situ hybridization (FISH) identified a novel small amplicon centered at PARD6B in 5 cell lines, with copy number ranging from 7 to 27. The presence of the PARD6B amplicon correlated with PARD6B transcript and PAR6B protein abundance. Expression of related isoforms PARD6A and PARD6G were detectable at significantly lower levels. PARD6B overexpression correlated with TJ network formation in cultured cell monolayers. SiRNA-mediated inhibition of PAR6B in MCF7 resulted in loss of TJ assembly and membrane localization of atypical PKCζ (aPKC), but did not affect adherens junction formation. SiRNA-mediated inhibition of CDC42 in MCF7 also resulted in loss of TJ networks, confirming the requirement of a complete PAR6-aPKC-CDC42-PAR3 complex to activate and stabilize TJs. Immunohistochemical analysis of PAR6B expression on breast tumor microarrays indicated exquisite epithelial cell-specificity. Few quantitative differences in staining were observed between normal epithelium and adjacent tumor margins. However staining appeared reduced and cytoplasmic in more poorly differentiated tumors. We propose that quantitative imbalances in the components of pathways governing normal epithelial cell polarity arising from gain or loss of function may radically alter epithelial cell architecture and contribute to tumor progression.
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Dionisio KL, Howie SRC, Dominici F, Fornace KM, Spengler JD, Adegbola RA, Ezzati M. Household concentrations and exposure of children to particulate matter from biomass fuels in The Gambia. Environ Sci Technol 2012; 46:3519-27. [PMID: 22304223 PMCID: PMC3309066 DOI: 10.1021/es203047e] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Particulate matter (PM) is an important metric for studying the health effects of household air pollution. There are limited data on PM exposure for children in homes that use biomass fuels, and no previous study has used direct measurement of personal exposure in children younger than 5 years of age. We estimated PM(2.5) exposure for 1266 children in The Gambia by applying the cookhouse PM(2.5)-CO relationship to the child's CO exposure. Using this indirect method, mean PM(2.5) exposure for all subjects was 135 ± 38 μg/m(3); 25% of children had exposures of 151 μg/m(3) or higher. Indirectly estimated exposure was highest among children who lived in homes that used firewood (collected or purchased) as their main fuel (144 μg/m(3)) compared to those who used charcoal (85 μg/m(3)). To validate the indirect method, we also directly measured PM(2.5) exposure on 31 children. Mean exposure for this validation data set was 65 ± 41 μg/m(3) using actual measurement and 125 ± 54 μg/m(3) using the indirect method based on simultaneously-measured CO exposure. The correlation coefficient between direct measurements and indirect estimates was 0.01. Children in The Gambia have relatively high PM(2.5) exposure. There is a need for simple methods that can directly measure PM(2.5) exposure in field studies.
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Affiliation(s)
- Kathie L Dionisio
- Department of Global Health and Population, Harvard School of Public Health, Boston, MA, USA
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
| | - Stephen RC Howie
- Child Survival Theme, Medical Research Council, The Gambia Unit, Fajara, The Gambia
| | - Francesca Dominici
- Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA
| | - Kimberly M Fornace
- Veterinary Epidemiology and Public Health Group, Royal Veterinary College, London, UK
| | - John D Spengler
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
| | - Richard A Adegbola
- Child Survival Theme, Medical Research Council, The Gambia Unit, Fajara, The Gambia
- Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Majid Ezzati
- MRC-HPA Center for Environment and Health, Department of Epidemiology and Biostatistics, Imperial College London, London, UK
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
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Dionisio KL, Howie SRC, Dominici F, Fornace KM, Spengler JD, Donkor S, Chimah O, Oluwalana C, Ideh RC, Ebruke B, Adegbola RA, Ezzati M. The exposure of infants and children to carbon monoxide from biomass fuels in The Gambia: a measurement and modeling study. J Expo Sci Environ Epidemiol 2012; 22:173-81. [PMID: 22166810 DOI: 10.1038/jes.2011.47] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 08/12/2011] [Indexed: 05/21/2023]
Abstract
Smoke from biomass fuels is a risk factor for pneumonia, the leading cause of child death worldwide. Although particulate matter (PM) is the metric of choice for studying the health effects of biomass smoke, measuring children's PM exposure is difficult. Carbon monoxide (CO), which is easier to measure, can be used as a proxy for PM exposure. We measured the exposure of children ≤ 5 years of age in The Gambia to CO using small, passive, color stain diffusion tubes. We conducted multiple CO measurements on a subset of children to measure day-to-day exposure variability. Usual CO exposure was modeled using a mixed effects model, which also included individual and household level exposure predictors. Mean measured CO exposure for 1181 children (n=2263 measurements) was 1.04 ± 1.46 p.p.m., indicating that the Gambian children in this study on average have a relatively low CO exposure. However, 25% of children had exposures of 1.3 p.p.m. or higher. CO exposure was higher during the rainy months (1.33 ± 1.62 p.p.m.). Burning insect coils, using charcoal, and measurement done in the rainy season were associated with higher exposure. A parsimonious model with fuel, season, and other PM sources as covariates explained 39% of between-child variation in exposure and helped remove within-child variability.
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Affiliation(s)
- Kathie L Dionisio
- Department of Global Health and Population, Harvard School of Public Health, Boston, Massachusetts, USA
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Dionisio KL, Howie S, Fornace KM, Chimah O, Adegbola RA, Ezzati M. Measuring the exposure of infants and children to indoor air pollution from biomass fuels in The Gambia. Indoor Air 2008; 18:317-27. [PMID: 18422570 DOI: 10.1111/j.1600-0668.2008.00533.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
UNLABELLED Indoor air pollution (IAP) from biomass fuels contains high concentrations of health damaging pollutants and is associated with an increased risk of childhood pneumonia. We aimed to design an exposure measurement component for a matched case-control study of IAP as a risk factor for pneumonia and severe pneumonia in infants and children in The Gambia. We conducted co-located simultaneous area measurement of carbon monoxide (CO) and particles with aerodynamic diameter <2.5 microm (PM(2.5)) in 13 households for 48 h each. CO was measured using a passive integrated monitor and PM(2.5) using a continuous monitor. In three of the 13 households, we also measured continuous PM(2.5) concentration for 2 weeks in the cooking, sleeping, and playing areas. We used gravimetric PM(2.5) samples as the reference to correct the continuous PM(2.5) for instrument measurement error. Forty-eight hour CO and PM(2.5) concentrations in the cooking area had a correlation coefficient of 0.80. Average 48-h CO and PM(2.5) concentrations in the cooking area were 3.8 +/- 3.9 ppm and 361 +/- 312 microg/m3, respectively. The average 48-h CO exposure was 1.5 +/- 1.6 ppm for children and 2.4 +/- 1.9 ppm for mothers. PM(2.5) exposure was an estimated 219 microg/m3 for children and 275 microg/m3 for their mothers. The continuous PM(2.5) concentration had peaks in all households representing the morning, midday, and evening cooking periods, with the largest peak corresponding to midday. The results are used to provide specific recommendations for measuring the exposure of infants and children in an epidemiological study. PRACTICAL IMPLICATIONS Measuring personal particulate matter (PM) exposure of young children in epidemiological studies is hindered by the absence of small personal monitors. Simultaneous measurement of PM and carbon monoxide suggests that a combination of methods may be needed for measuring children's PM exposure in areas where household biomass combustion is the primary source of indoor air pollution. Children's PM exposure in biomass burning homes in The Gambia is substantially higher than concentrations in the world's most polluted cities.
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Affiliation(s)
- K L Dionisio
- Harvard School of Public Health, Boston, MA 02115, USA
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